Test 4. Chapter 16

Question 1

what are the 4 general types of cell communication?

Answer 1

contact dependent

paracrine

synaptic

endocrine

Question 2

the _________ bind to the receptor protein

Answer 2

signaling molecule

Question 3

The ________ activates intracellular signalling proteins that intiate a ___________–

Answer 3

receptor

signaling cascade

Question 4

The signaling cascade influences a ___________, altering this target protein and thus altering the behavior of thecell

Answer 4

target protein

Question 5

_________________ extracellular signal molecule (hormone) that binds to and activates receptor

Answer 5

first messengers

Question 6

_______________: small molecules that produce in large numbers as a consequence of receptor activation

Answer 6

secondary messengers

Question 7

_________________: pass the signal on to the next intracellular signaling protein

Answer 7

relay proteins

Question 8

_____________: link one signaling protein to another, but do not convey the signal themselves. Critcal for the formation of signaling complexes

Answer 8

adapter proteins

Question 9

_____________: proteins that bind multiple signaling proteins together in a functional complex and often hold them in a specific location

Answer 9

scaffold proteins

Question 10

_______________: amplify the signal, often by generating second messengers (ion channels and enzymes)

Answer 10

amplifier proteins

Question 11

______________: locate signaling proteins in a precise location in the cell by tethering them to the membrane or cytoskeleton

Answer 11

anchoring protein

Question 12

_____________: these are activated at the cell surface by receptors and translocate into the nucleus to regulate gene expression

Answer 12

gene regulatory proteins

Question 13

what are some common secondary messengers?

Answer 13

cAMP, cGMP, calcium ion, IP3, DAG

Question 14

Name two types of molecular switches? (to turn on)

Answer 14

signaling by phosphorlation

signaling by GTP binding

Question 15

Cells often require multiple signal proteins coincidentally to trigger a response. Often,
multiple signals require ______________- which require more than one input signal to
generate an output signal that propagates a downstream signaling cascade.

Answer 15

integrator proteins

Question 16

G- protein coupled receptors (GPCR) change conformation in response to _______ binding and activated __________–

Answer 16

ligand binding

activated G proteins

Question 17

in heterotrimeric G protein pathways what are involved?

Answer 17

stimulus/ligand

receptor

g protein

effector

Question 18

G protein coupled receptors (GPCR) represent _____________ of the current drug target

Answer 18

50-60

Question 19

inactivated heterotrimeric G protein is bound to __________-

Answer 19

GDP

Question 20

G- protein mediated activation of ____________ by hormone binding leads to creation of CAMP

Answer 20

adenylate cyclase

Question 21

most effects of cAMP are mediated by protein….________

Answer 21

protein kinase A (PKA)

Question 22

Gαq activates phospholipase C, which cleaves the membrane lipid phosphatidylinositol bisphosphate into two second messengers:___________________

Answer 22

inositol 1, 4, 5-trisphosphate (IP3)

diacylglycerol (DAG

Question 23

What enzyme is used in the reaction where Pip3 makes DAG?

Answer 23

phospholipase C

Question 24

in phosphoinositide cascade how messengers are required for activation of PKC?

Answer 24

2 messengers

Question 25

how does GPCR signaling specificity occur?

Answer 25

multiple physiological response

Question 26

Signalling specificity is achieved by scaffolding in yeast

Scaffolding of _______________is also seen in mammalian cells

Answer 26

MAPK cascade

Question 27

G proteins spontaneously reset themselves through _________

Answer 27

GTP hydrolysis

Question 28

Know dissociation

Answer 28

???????

Question 29

describe guanine analogs and their roles?

Answer 29

N-methylated analogs of guanine

Mimic GTP, bind and stimulate G-proteins

“natural” stimulants

Question 30

Some receptors dimerize in response to lingand binding and recruit ______________-

Answer 30

tyrosine kinases

Question 31

each JAK phosphorylates its partner on a typrosine reside, activating the two ___________

Answer 31

kinases

Question 32

what intially triggers change in gene expression?

Answer 32

ras activation

GTP hydrolysis

MAP kinase phosphorylation

growth factor-receptor binding

Question 33

Ras belongs to another class of signaling _________

Answer 33

g protein

Question 34

Why care about ras?

Answer 34

ras is most common onogene in human cancer

The Ras pathway provides a focus on the origins of cancer at the molecular level.

Ras is a key cellular protein for cell growth, differentiation and survival.

Question 35

the polypeptide hormone __________ is secreted when the blood is rich in glucose. It is the biochemical signal for fed state

Answer 35

insulin

Question 36

The insulin receptor is a dimer that closes around a bound insulin molecule.

The insulin receptor is a ___________-

Receptor dimers form a insulin binding, leading to _____________ and activation of the kinase domains

Answer 36

tyrosine kinase

cross- phosphorylation

Question 37

the activated insulin receptor kinase intiates a ___________—

Answer 37

kinase cascade

Question 38

what is the action of lipid kinase in insulin signaling… give an example

Answer 38

phosphatidylinositide 3 kinase is used to phophoralate Pip2 to Pip3

Question 39

how does the body inactivate the insulin cascade?

Answer 39

Protein phosphatases remove phosphates from the activated proteins in the insulin signal transduction pathway, terminating the insulin signal.

Lipid phosphatases contribute to signal termination by converting PIP3 into PIP2.